Work is currently underway in the area of service interoperability for Ethernet passive optical networks (EPON). This work is likely to result in new standards. Work is being done and definitions being formed in the area of Optical Link Protection, know as fiber protection or redundancy, and in the area of power save.
A major problem with power save is the detection of fiber failure during power save, since both the OLT and the ONUs rely on a valid signal in order to detect fiber failure. However, the OLT may not detect a valid signal for sleeping ONUs (ONUs in sleep-mode). Correspondingly, an ONU in Tx/Rx sleep-mode may not detect a fiber failure and may not be aware of the OLTs switchover. In addition to solving the problem of combined fiber protection and power savings, a solution is also needed for providing this combination when security is enabled.
There is therefore a need to define an integration (cross correlation) of fiber protection, power save, and encryption.